KR20120043956A - A production method of brick using waste materials of steel making, and brick produced by the same - Google Patents

Abstract

PURPOSE: A manufacturing method of a block using by-products from an iron making process and a block manufactured with the method are provided to satisfy an absorption rate of 7% or less and a compressive strength of 80kg/cm^2 or more by using dust and sludge generated during an iron process. CONSTITUTION: A manufacturing method of a block using by-products from an iron making process comprises next steps: forming a mixture by mixing dust and sludge generated in an iron manufacturing process; mixing cement, fine aggregate, and moisture with the mixture(S10); compression-molding into a block shape(S20); steam curing the block shape(S30); and natural curing the block shape(S40). In the mixing step, a mixing ratio of the dust to the sludge is 2:1-8:1 wt%.

Description

A production method of brick using waste materials of steel making, and brick produced by the same}

The present invention relates to a block manufacturing method using steel by-products, and more particularly to a block manufacturing method using a steel production by-product to produce a block for embedding using dust and sludge generated in the steelmaking process, and the block produced therefrom. .

Common steelmaking processes include steelmaking, steelmaking, continuous casting and rolling.

The iron making process is the process of putting iron ore in the blast furnace and burning coke to remove and dissolve the oxygen in the iron ore to make molten iron. It is the process of producing molten steel of desired components and proper temperature.

Continuous casting process is the process of injecting the produced molten steel into the mold, drawing and cooling continuously to manufacture slabs, blobs, and billets of semi-finished products. It is a process of producing a product having a predetermined shape and dimensions in a hot rolling mill after transferring to a factory and reheating.

An object of the present invention is a block manufacturing method using a steelmaking by-product to produce a block that satisfies the compressive strength of 80kg / ㎠ or more, absorption rate less than 7% by using dust and sludge generated during the steelmaking process and no harmful substances are eluted and produced therewith To provide blocks.

According to a feature of the present invention for achieving the above object, the present invention comprises a mixing step of forming a mixture by mixing dust and sludge generated in the steelmaking process; adding and mixing cement, fine aggregate, water to the mixture A compression step of molding into a block shape by compression molding; Steam curing step of curing the block shape; And a natural curing step of naturally curing the steam-cured block shape.

The mixing ratio of wt% of the dust and sludge is from 2: 1 to 8: 1.

The dust includes at least one selected from raw dust, columnar dust, sintered EP dust, sintered bag filter dust, playing dust, and transport and unloading dust.

The sintered EP dust and the sintered bag filter dust contain less than 30wt% of the total content of the mixture.

The sludge includes at least one selected from blast furnace sludge, performance sludge, thick plate sludge, hot rolled sludge, feed drainage sludge and drainage terminal sludge.

The cement is added 15 to 21wt% with respect to 100wt% of the mixture.

The fine aggregate, 6 ~ 8wt% is added to 100wt% of the mixture.

The moisture is added 4 ~ 8wt% with respect to 100wt% of the mixture.

The steam curing step maintains the molded block shape at a temperature of 70 ~ 85 ℃ 15 ~ 28 hours.

It consists of dust, sludge, cement, fine aggregates generated in the steelmaking process, the compressive strength is 100 ~ 140kgf / ㎠, the absorption rate is 3 ~ 5%.

The dust includes at least one selected from raw dust, columnar dust, sintered EP dust, sintered bag filter dust, playing dust, and transport and unloading dust.

The sludge includes at least one selected from blast furnace sludge, performance sludge, thick plate sludge, hot rolled sludge, feed drainage sludge and drainage terminal sludge.

The present invention produces a block by curing and molding cement, fine aggregate, and water in the dust and sludge generated in the steel mill. The manufactured blocks had physical strength of 100 ~ 140kg / ㎠ compressive strength and 3 ~ 5% absorption rate, and showed the physical properties over the general brick standard.

Therefore, it is possible to reduce the costs incurred in the disposal of by-products generated in the steel mill, and to be recycled to the aggregate for reclaiming the shared water, thereby improving the environment.

1 is a process diagram showing a block manufacturing method using the steel by-product according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail.

In the block manufacturing method using the steelmaking by-product of the present invention, the dust and sludge produced in the steelmaking process is mixed to form a mixture (S10), cement, fine aggregate, and water is added to the mixture and mixed and then compression molded into a block shape. Molding (S20). Thereafter, the block shape is steam cured (S30), natural curing (S30) to produce a final block.

The prepared blocks are used as aggregates for co-surface reclamation. The prepared block has a compressive strength of 100-140kgf / ㎠, an absorption rate of 3-5%, and satisfies the hazardous substance dissolution stability test criteria.

The mixture is a mixture of dust and sludge in a ratio of 2: 1 to 8: 1 [wt%].

The dust includes at least one selected from raw dust, columnar dust, sintered EP dust, sintered bag filter dust, playing dust, and transport and unloading dust.

Raw material dust is dust from blast furnace fuel, columnar dust is dust generated in blast furnace main phase (outline part), and sintered EP dust is dust collected in electric furnace dust collector. In addition, the sintered bag filter dust is dust collected in the bag filter of the sintering machine, the playing dust is dust generated during the playing process, the transport unloading dust is dust generated during the transport and unloading process.

The sludge includes at least one selected from blast furnace sludge, playing sludge, thick plate sludge, hot rolled sludge, water drainage sludge and drainage terminal sludge.

The dust and sludge contains trace amounts of iron and contains components that adversely affect the steelmaking process equipment and product quality, such as S, Zn, and K, so that they are not recycled and landfilled or consigned.

In the case of landfill, the secondary environmental pollution is caused, and the drying process is carried out to reduce the weight of dust and sludge during landfill, so energy consumption is also high.

Therefore, dust and sludge, which are by-products of the steelmaking process, are recycled, but they are manufactured as blocks through the work of fixing and solidifying harmful substances and used as aggregate for landfilling of common water.

The ratio of dust and sludge in the mixture is within the range to adequately control the water content. Dust controls the water content of the mixture, and as the ratio of sludge increases, the water content of the mixture increases.

When the mixture is less than 2: 1 in the ratio of dust and sludge, the ratio of sludge is increased to increase the water content, so that a flow phenomenon occurs during molding and workability is reduced. On the other hand, when the ratio of dust and sludge exceeds 8: 1, the ratio of dust is increased and water content is reduced, so that the mixing efficiency is lowered and curing is delayed.

Sintered EP dust and sintered bag filter dust in dust are included in less than 30wt% of the total content of the mixture. Since the sintered EP dust and the sintered bag filter dust contain a large amount of Ca compound, when it exceeds 30wt% of the total content of the mixture, the expansion is caused by the large amount of the Ca compound component, thus causing cracking and decreasing strength.

Cement, fine aggregates, and moisture are for solidifying the mixture.

Specifically, cement is added to fix the hazardous substances and to solidify the mixture. For cement, 15 to 21 wt% is added to 100 wt% of the mixture. For example, if the mixture is 100g, 15 to 21g of cement is mixed.

When cement is added below 15 wt% with respect to 100 wt% of the mixture, the strength of the molded block is lowered and the immobilization capacity of the harmful heavy metals contained in trace amount is reduced due to the characteristics of dust and sludge which are steel by-products. If the immobilization capacity is lowered, heavy metals may leak into the seawater when the manufactured blocks are used for landfill reclaim. On the other hand, when the cement is added in excess of 21wt% with respect to 100wt% of the mixture, the amount of voids increases due to the lack of relative mixture content, and the strength is lowered.

Fine aggregates ensure the strength of the blocks by reducing the voids in the sludge. Most of the mixture is composed of dust and sludge, so it is difficult to secure the strength of the block without adding fine aggregate. Fine aggregates are added in an amount of 6 to 8 wt% relative to 100 wt% of the mixture.

Residual aggregate is difficult to secure the strength of the produced block when added to less than 6wt% with respect to 100wt% of the mixture, it is not efficient to increase the operating cost if it exceeds 8wt%.

Moisture is added for cement curing. Moisture is added 4 to 8 wt% relative to 100 wt% of the mixture.

When moisture is added below 4 wt% with respect to 100 wt% of the mixture, cement curing, that is, the hydration reaction between cement and water is remarkably degraded, resulting in slow strength development and surface cracks in the manufactured blocks. On the other hand, when moisture is added in excess of 8 wt% with respect to 100 wt% of the mixture, the mixing efficiency may be lowered, the workability may be lowered, and the strength may be difficult to develop.

On the other hand, the raw materials added cement, fine aggregate, and water to the mixture is mixed in the raw material mixer. The raw materials mixed in the raw material mixer are supplied to a block molding machine, and are molded into a block shape of a cube in the block molding machine. The block molding machine may be a vibratory briquette.

Vibration briquette is based on the principle that the raw material is compacted as air is released.

The block shape may be formed into a hexahedral shape having a size of 80 × 80 × 60 mm to 240 × 240 × 150 mm. The molded block shape sequentially performs steam curing and natural curing.

Steam curing is to charge the molded block shape into the steam curing room and to maintain steam for 15 to 28 hours at a temperature of 70 ~ 85 ℃ while supplying steam. Steam curing is performed to develop the strength of the block. Natural curing alone is difficult to secure the desired strength and there is a problem in durability.

If the temperature during steam curing is less than 70 ℃, the natural curing time proceeds after a long time and the strength is lowered, if it exceeds 85 ℃ may cause cracks due to the high temperature.

If the steam curing time is less than 15 hours, it is difficult to secure the desired strength, and if the steam curing time exceeds 28 hours, the effect is saturated, which is not preferable in terms of energy saving. When steam curing is completed, naturally cure for 10 to 15 days to improve strength.

Block (m) prepared as described above is made of dust, sludge, cement, fine aggregate generated in the steelmaking process, the compressive strength is 100 ~ 140kgf / ㎠, the absorption rate is 3 ~ 5%.

The dust contains at least one selected from raw dust, columnar dust, sintered EP dust, sintered bag filter dust, playing dust and transport and unloading dust.Sludge is blast furnace sludge, cast sludge, thick plate sludge, hot rolled sludge, rapid drainage sludge, At least one selected from the drainage sludge is included.

Hereinafter, the embodiment of the present invention will be described in more detail. However, the examples and the like described below are for illustrating the present invention, and the present invention is not limited thereto and may be variously modified and changed.

<Examples>

The dust and sludge from the steelmaking process are loaded into the raw material mixer so that the ratio is 5: 1 [wt%]. In this process, the sintered EP dust and the sintered bag filter dust in the dust are included in less than 30wt% of the total content of the dust and sludge charged into the raw material mixer.

After that, the cement, fine aggregate, and water are further charged into the raw material charging machine and mixed for 7 minutes.

At this time, cement is added to the mixture of dust and sludge 100wt%, 18wt%, fine aggregate is added 7wt%, moisture is added 6wt%.

When the mixing is 7 minutes in the raw material mixer, the mixed raw materials are introduced into a block molding machine and molded into a hexahedral block shape having a size of 80 × 80 × 60 mm.

The molded block is spontaneously cured for 15 days after steam curing is maintained for 20 hours in a steam curing room maintained at 80 ℃.

Table 1 analyzes the components of the blocks prepared by the method of the example.

(Unit: wt%) T.Fe M-Fe SiO ₂ Al ₂ O ₃ CaO MgO Mn P ZnO C S 52.19 28.12 2.68 0.54 11.44 1.04 0.46 0.09 1.35 1.97 0.12

Table 1 shows that the components of the block are similar to natural aggregate and cement.

Table 2 measures the physical properties of the blocks produced by the method of the example.

Compressive strength 100 ~ 140kgf / ㎠ Absorption rate 3-5%

According to Table 1 and Table 2, it can be seen that the block of the present invention satisfies the physical conditions of the brick standard or more. (Standard bricks have a compressive strength of 80kg / ㎠ or more and an absorption rate of 7% or less.)

Table 3 is an evaluation of the blocks produced by the method of Example using the dissolution test method of the waste process test method.

(Unit: mg / L) division Pb Cu As Hg CN Hexavalent chromium CD Organic phosphorus PCB TCE PCE Example 0.07 0.4 N.D. N.D. 0.8 N.D. 0.01 N.D. N.D. N.D. N.D. Environment
Reference value 3
under 3
under 1.5
under 0.005
under One
under 1.5
under 0.3
under One
under 0.1
under 0.3
under 0.1
under

[CN: Copernium, PCB: Polychlorinated biphenyl, TCE: Trichloroethylene, PCE: Tetrachloroethylene]

Here, environmental standards are based on the Exhibit 1 of the Enforcement Rules of the Waste Management Act.

According to Table 3, the prepared blocks meet the environmental standards and were not eluted at all for As, Hg, hexavalent chromium, organophosphorus, PCB, TCE, and PCE.

Through this, when the dust and sludge formed in the steelmaking process are formed into blocks, the compressive strength and the absorption rate satisfy the standard value of the brick or higher, and can be used as aggregate for reclaiming the shared water surface, and it is harmless to the environment because no harmful substances are eluted. It can be seen.

In addition, unlike the landfill, the method does not cause secondary environmental pollution and does not require a drying process for weight reduction of dust and sludge, and thus is environmentally friendly and energy-saving.

The present invention is not limited to the above embodiments but will be implemented in various different forms, only the present embodiments to complete the disclosure of the present invention, to fully inform those skilled in the art the scope of the invention It is provided.

S10: Mixing Step S20: Molding Step
S30: Steam Curing Stage S40: Natural Curing Stage
m: block

Claims (12)

A mixing step of forming a mixture by mixing dust and sludge generated in the steelmaking process;
A molding step of adding a cement, fine aggregate, and water to the mixture, mixing the mixture, and then molding the block into a block shape by compression molding;
Steam curing step of curing the block shape; And
Block manufacturing method using the steel by-products, characterized in that it comprises a natural curing step of natural curing the steam-cured block shape. The method according to claim 1,
In the mixing step
Mixing ratio of the wt% of the dust and sludge is 2: 1 ~ 8: 1 block manufacturing method using steel by-products, characterized in that. The method according to claim 1,
The dust is
Raw material dust, columnar dust, sintered EP dust, sintered bag filter dust, playing dust, transport unloading dust block manufacturing method using steel by-products, characterized in that it comprises at least one type. The method according to claim 3,
The sintered EP dust and the sintered bag filter dust is less than 30wt% relative to the total content of the mixture manufacturing method using a steel by-products. The method according to claim 1,
The sludge
Block manufacturing method using steel by-products, characterized in that it comprises at least one selected from blast furnace sludge, performance sludge, thick plate sludge, hot rolled sludge, water drainage sludge, drainage terminal sludge. The method according to claim 1,
The cement is,
With respect to the mixture 100wt%, 15 ~ 21wt% block manufacturing method using steel by-products, characterized in that added. The method according to claim 1,
The fine aggregate,
With respect to the mixture 100wt%, 6 ~ 8wt% block manufacturing method using steel by-products, characterized in that added. The method according to claim 1,
The moisture,
With respect to the mixture 100wt%, 4 ~ 8wt% block manufacturing method using steel by-products, characterized in that added. The method according to claim 1,
The steam curing step
Block manufacturing method using steel by-products, characterized in that for maintaining the molded block shape at a temperature of 70 ~ 85 ℃ 15 ~ 28 hours. Including dust, sludge, cement, fine aggregates generated in the steelmaking process,
Block using steel by-products, characterized in that the compressive strength is 100 ~ 140kgf / ㎠, the absorption rate is 3 ~ 5%. The method according to claim 10,
The dust is
Block using steel by-products, characterized in that it comprises at least one selected from the source dust, columnar dust, sintered EP dust, sintered bag filter dust, playing dust, transport unloading dust. The method according to claim 10,
The sludge
Block using steel by-products, characterized in that it comprises at least one selected from blast furnace sludge, performance sludge, thick plate sludge, hot rolled sludge, water drainage sludge, drainage terminal sludge.

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